Computer analysis, including application of several new algorithms, have been carried out in close collaboration with experimental laboratories, and new computational strategies have been developed in response to questions arising about the structures, functions, interactions and genetics of the proteins of interest. Several important parasites and pathogens, including the malaria parasite Plasmodium falciparum, show extreme bias in the residue compositions of both genes and proteins. These compositional properties, together with questions about the roles of low-complexity, nonglobular and conformationally mobile parts of proteins, are relevant to aspects of the pathogenicity of these organisms and their interactions with the mammalian hosts, with applications to vaccine design and the development of new insights into drug resistance. - Computer algorithms, protein sequences, genome sequences, parasites, bacteria, archaea, compositional bias